Ensuring performance isolation and differentiation among workloads is a basic requirement in all computational environments where physical resources are shared among multiple “customers”. This is typical in emerging consolidated data centers, such as those implemented by HP's Utility Data Center. For example, this is a problem for storage sharing, since storage access contributes substantially to the overall performance perceived by the applications running in consolidated data centers. The same problem applies to resources other than storage (including CPUs or fractions of them, memory, network bandwidth, and other computing resources).
It is important to ensure that customers of consolidated data centers receive the resources and performance (e.g., service level objectives) they are entitled to. More specifically, the performance of workloads must be isolated from the activities of other workloads that share the same infrastructure. Further, available resources should be shared among workloads according to their relative importance. Ensuring that customers get the resources they pay for (and do so in a provable way) is a potential value-added service that HP products such as the UDC could offer to differentiate them from the competition.
Existing state-of-the-art management tools rely on automatic provisioning of adequate resources to achieve certain performance goals. Although resource provisioning is necessary to meet the basic performance goals of workloads, it is not intended to handle rapid workload fluctuations and system changes and short-term peak demands. Further, it may be prohibitively expensive to provision for a worst case scenario. In fact, it may be impossible to provision for a worst-case scenario since the worst-case scenario is typically not known in advance of its occurrence. Many of these issues may be addressed by controlling access to a computing resource.
Therefore, what is needed is a method of controlling access to a computing resource. It is toward this end that the present invention is addressed.